Steering efficiency of a ultrarelativistic proton beam in a thin bent crystal

Bagli, Enrico; Lietti, Daniela; Vallazza, Erik; Guidi, Vincenzo; Bandiera, Laura; De Salvador, Davide; Berra, Alessandro; Mazzolari, Andrea; Prest, Michela

doi:10.1140/epjc/s10052-014-2740-7

Article
Report number	arXiv:1311.4674
Title	Steering efficiency of a ultrarelativistic proton beam in a thin bent crystal
Author(s)	Bagli, Enrico (INFN, Ferrara ; Ferrara U.) ; Bandiera, Laura (INFN, Ferrara ; Ferrara U.) ; Guidi, Vincenzo (INFN, Ferrara ; Ferrara U.) ; Mazzolari, Andrea (INFN, Ferrara ; Ferrara U.) ; De Salvador, Davide (INFN, Legnaro ; Padua U.) ; Berra, Alessandro (Insubria U., Como ; INFN, Milan Bicocca) ; Lietti, Daniela (Insubria U., Como ; INFN, Milan Bicocca) ; Prest, Michela (Insubria U., Como ; INFN, Milan Bicocca) ; Vallazza, Erik (INFN, Trieste)
Publication	2014-01-28
Imprint	19 Nov 2013
Number of pages	16
Note	Comments: 16 pages, 6 figures 16 pages, 6 figures
In:	Eur. Phys. J. C 74 (2014) 2740
DOI	10.1140/epjc/s10052-014-2740-7
Subject category	Accelerators and Storage Rings
Accelerator/Facility, Experiment	CERN SPS
Test beam	H8
Abstract	Crystals with small thickness along the beam exhibit top performance for steering particle beams through planar channeling. For such crystals, the effect of nuclear dechanneling plays an important role because it affects their efficiency. We addressed the problem through experimental work carried out with 400 GeV/c protons at fixed-target facilities of CERN-SPS. The dependence of efficiency vs. curvature radius has been investigated and compared favourably to the results of modeling. A realistic estimate of the performance of a crystal designed for LHC energy including nuclear dechanneling has been achieved.
Copyright/License	publication: © 2014-2024 The Author(s) (License: CC-BY-4.0), sponsored by SCOAP³

$(a)-(b) Potential energy in the reference frame integral to crystal planes for $R = \infty$ (a) and $R = 3R_{c}$ evaluated through the ECHARM software \cite{PhysRevE.81.026708}. (b). Gray boxes highlight impact region which will cause particle to dechannel due to multiple scattering on nuclei and core electrons. Crossed box region is the impact region of particle with do not channel because of the presence of the crystal curvature. (c)-(d) Trajectories of 400 GeV/c proton interacting with a Si crystal with bending radius $R = \infty$ (c) and $R = 3R_{c}$ (d).$ $(a) Experimental setup used during data taking at H8 external line of the SPS accelerator at CERN. Three Si strip detector (S) were mounted $\sim10$ m one from another in order to reach a $\mu$rad angular resolution in the reconstruction of the particle track. The crystal was mounted on a high-resolution two-axis (G) offering an accuracy of 1.0 $\mu$rad. (b) A sketch of the bent Si strip.$